A new energy vehicle chassis trailing arm laser composite welding system

Abstract

The application discloses a new energy automobile chassis longitudinal arm laser composite welding system, and relates to the technical field of new energy automobile chassis longitudinal arm welding. The application can automatically adjust the energy output of laser and electric arc according to the real-time parameters of the welding area, ensure the stability and defect-free of the weld forming, and especially show excellent flexible adaptation ability when dealing with different specifications of longitudinal arms. In addition, the pressure closed-loop control of the clamping system effectively avoids the workpiece clamping deformation, and the introduction of the water cooling system further optimizes the heat input management, so that the deformation after welding is strictly controlled within 0.5mm, and an additional shaping process is not needed. The linkage design of the dust removal system and the welding station house not only improves the working environment, but also improves the safety and operation convenience. The overall scheme has high efficiency, reliability and environmental protection, provides a new technical solution for the new energy automobile industry, and has important popularization and application value.

Description

Technical Field

[0001] This invention relates to the field of longitudinal arm welding technology for new energy vehicle chassis, specifically to a laser composite welding system for longitudinal arms of new energy vehicle chassis. Background Technology

[0002] As a core load-bearing component connecting the vehicle body and suspension, the trailing arm of a new energy vehicle chassis must meet stringent requirements for high strength (tensile strength ≥ 800 MPa), lightweight (materials are mostly third-generation hot-formed steel or 6-series aluminum alloys) and dimensional accuracy (deformation after welding ≤ 0.5 mm). Its welding quality directly affects the safety and range of the entire vehicle.

[0003] Currently, the industry mainly uses single laser welding or laser-arc hybrid welding technology for welding longitudinal arms, but the following prominent problems exist:

[0004] 1) Poor welding quality stability: In existing laser hybrid welding systems, the energy output of laser and electric arc is mostly matched with fixed parameters, which cannot be adjusted in real time according to the gap (0.1-0.5mm), plate thickness (2-5mm) and joint type (lap joint, corner joint) of the longitudinal arm welding area. This can easily lead to incomplete fusion (especially when the gap exceeds 0.3mm), porosity (accounting for 5%-8% in aluminum alloy welding) or hot cracking (hardness fluctuation of ≥15% in the heat-affected zone of high-strength steel welding).

[0005] 2) Insufficient flexibility and adaptability: Traditional systems require manual recalibration of more than 10 parameters such as laser focus position and arc voltage for different specifications of trailing arms (such as length differences of 50-150mm and changes in cross-sectional shape). The changeover time is as long as 2-3 hours, which is difficult to meet the production needs of new energy vehicles with multiple varieties and small batches (a single production line needs to be compatible with 3-5 trailing arm models).

[0006] 3) Low heat input control precision: Single laser welding has a concentrated heat input but poor molten pool fluidity. Excessive heat input in arc welding can easily lead to torsional deformation of the longitudinal arm exceeding 0.8mm after welding, requiring an additional straightening process. This not only reduces production efficiency (straightening time accounts for 15% of each shift) but may also affect weld fatigue strength due to work hardening (reducing it by about 10%-15%). Therefore, we propose a laser-hybrid welding system for the longitudinal arms of new energy vehicle chassis. Summary of the Invention

[0007] The purpose of this invention is to provide a laser composite welding system for the longitudinal arms of a new energy vehicle chassis in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0009] A laser composite welding system for the longitudinal arms of a new energy vehicle chassis includes:

[0010] The control system consists of a PLC control cabinet and a robot control cabinet. The PLC control cabinet is the core control unit of the system, which realizes parameter setting, real-time monitoring, fault alarm and data storage, and uploads data to the cloud platform through the G module. The robot control cabinet is used to control the movement trajectory of the robot body.

[0011] The clamping system consists of a base and a clamping unit; wherein, the base is used for modular positioning, and the clamping unit is used for synchronous clamping of the longitudinal arm at multiple positions, and workpiece deformation is avoided by pressure closed-loop control;

[0012] The welding system consists of a welding machine, a wire feeder, and a welding torch sandblasting cleaning station; wherein, the welding machine is used to achieve single-pass penetration of the longitudinal arm, the wire feeder is used to provide welding wire to the welding machine, and the welding torch sandblasting cleaning station is used to automatically clean the welding torch nozzle during the welding interval to remove welding slag, spatter, and oxide layer.

[0013] A light source room, which is used to provide stable laser energy for the welding machine;

[0014] The auxiliary system consists of a regulated power supply, a water cooling system, and a hydraulic station; wherein, the regulated power supply is used to stabilize the output of three-phase voltage and suppress grid fluctuations, the water cooling system is used to provide water cooling to the clamping unit, the welding machine, and the light source room, and the hydraulic station is used to provide stable hydraulic power to the clamping unit;

[0015] The dust removal system is used to capture the fumes generated during welding and purify them through high-efficiency filter elements and activated carbon adsorption, thus improving the welding working environment.

[0016] The welding station is used to provide a closed and safe welding environment, and the welding station is linked with the dust removal system to achieve air circulation.

[0017] Furthermore, the PLC control cabinet is connected to the robot control cabinet, hydraulic station, welding machine, and dust removal system via an interface; it collects sensor data from the water cooling system and hydraulic clamping fixture via an analog input module; and it controls the start and stop of the wire feeder, cleaning station, and regulated power supply via a digital output module. The PLC control cabinet is made of IP-rated cold-rolled steel plate and has a built-in cooling fan with an air volume of 200m³ / h and a temperature and humidity sensor with a measurement range of 0-60℃ / 20%-90%RH.

[0018] Furthermore, the robot control cabinet is connected to the robot body via an EtherCAT bus, connected to the welding machine via an IO interface, and interacts with the PLC control cabinet via a Profinet interface. The robot control cabinet is also compatible with a six-axis welding robot and integrates a six-axis independently driven servo driver, a motion control card supporting the EtherCAT bus, an emergency stop control loop, and a robot motion database with 100 pre-stored longitudinal arm welding trajectory programs.

[0019] Furthermore, the clamping unit includes eight sets of hydraulic clamping cylinders and four sets of positioning pins. The hydraulic clamping cylinders are used to fix the key force-bearing parts of the chassis longitudinal arm workpiece, and work with the four sets of positioning pins to achieve precise positioning and reliable clamping of the workpiece, preventing the workpiece from shifting due to thermal deformation or vibration during welding. The hydraulic clamping cylinders have a cylinder diameter of 80mm, a stroke of 50mm, and a working pressure of 10-16MPa. The positioning pins have a diameter of 20mm and a positioning accuracy of ±0.03mm.

[0020] Furthermore, each of the hydraulic clamping cylinders is equipped with a detection module, which integrates a pressure sensor and a displacement sensor to monitor the clamping force of the hydraulic clamping cylinder and the insertion depth of the positioning pin in real time.

[0021] Furthermore, the wire feeder is connected to the welding machine via a welding wire conduit, wherein the conduit has an inner diameter of 1.5 mm, a length of 5 m, and is made of nylon.

[0022] Furthermore, the output of the regulated power supply is connected to the PLC control cabinet and the robot control cabinet via a three-phase five-wire cable to provide a stable power supply. The water cooling system is connected to the light source room, the welding machine, and the clamping unit via PU cooling water pipes. The hydraulic station is connected to the clamping unit via high-pressure oil pipes.

[0023] Furthermore, the light source room is equipped with an optical path monitoring sensor for real-time monitoring of laser energy, and the light source room is connected to the laser input interface of the welding machine via an optical fiber with a core diameter of 50μm, a length of 10m, a numerical aperture of 0.22, and an outer armor protection layer.

[0024] Furthermore, the dust removal system is connected to the dust control unit inside the welding station via a corrugated dust suction pipe. The corrugated dust suction pipe has an inner diameter of 150mm, a length of 6m, and its body is made of flame-retardant PVC material with an oxygen index ≥32.

[0025] Furthermore, the welding station is made entirely of aluminum alloy with an anodized surface treatment process to prevent light emission. The welding station is equipped with an infrared grating with a protection height of 2000mm and a response time of <0.01s, a smoke detector with a detection concentration of 0.1-10%LEL, emergency lighting with a continuous power supply time of ≥90min, and a ventilation skylight with an opening angle of 0-90° that is electrically controlled.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. Quality Improvement: The weld pass rate has been increased from the current 85% to over 99%, the defect rate such as porosity and lack of fusion has been reduced by 90%, and the fluctuation range of weld tensile strength has been reduced to ±5%, meeting the service requirements of 1.5 million fatigue cycles for the longitudinal arm of new energy vehicle chassis.

[0028] 2. Efficiency optimization: Changeover time is reduced by 80%, and single-shift production capacity is increased by 25%; after eliminating the calibration process, the production cycle of a single piece is shortened by 12 minutes, and the annual production capacity can be increased by 30,000 units.

[0029] 3. Cost reduction: Due to the decrease in defect rate, rework costs are reduced by 60%; flexible adjustments reduce investment in special tooling, reducing equipment costs per production line by 15%; optimized heat input reduces material loss rate from 3% to 0.5%, saving approximately RMB 800,000 in raw material costs annually.

[0030] 4. Safety and Reliability: Improved longitudinal arm dimensional accuracy reduces chassis suspension assembly error by 0.2mm, improving overall vehicle driving stability by 10%; full-process quality traceability can quickly locate potential risks, reduce after-sales failure rate (expected to decrease by 40%), and enhance brand reputation.

[0031] 5. Technological Leadership: This system is the first to achieve an adaptive gradient ratio of laser-arc energy, breaking through the welding bottleneck of high-strength lightweight components for new energy vehicles, providing the industry with a replicable process solution, and promoting the large-scale application of laser composite welding technology in automobile chassis manufacturing. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention;

[0033] Figure 2 This is a system architecture diagram of the present invention;

[0034] Figure 3 This is the connection logic diagram of the present invention.

[0035] In the diagram: 1. Control system; 11. PLC control cabinet; 12. Robot control cabinet; 2. Clamping system; 21. Base; 22. Clamping unit; 221. Hydraulic clamping cylinder; 222. Positioning pin; 23. Detection module; 231. Pressure sensor; 232. Displacement sensor; 3. Welding system; 31. Welding machine; 32. Wire feeder; 33. Welding torch sandblasting cleaning station; 4. Light source room; 5. Auxiliary system; 51. Stabilized power supply; 52. Water cooling system; 53. Hydraulic station; 6. Dust removal system; 7. Welding station; 71. Infrared grating; 72. Smoke alarm; 73. Emergency lighting; 74. Ventilation skylight. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0037] Please see Figure 1 - Figure 3 This invention provides a laser composite welding system for the longitudinal arms of a new energy vehicle chassis, comprising:

[0038] Control system 1 consists of a PLC control cabinet 11 and a robot control cabinet 12. The PLC control cabinet 11 is the core control unit of the system, realizing parameter setting, real-time monitoring, fault alarm, and data storage, and uploading data to the cloud platform via a 4G module. The robot control cabinet 12 is used to control the robot's movement trajectory. With the cooperation of the PLC control cabinet 11 and the robot control cabinet 12, welding tasks can be completed accurately, improving production efficiency and welding quality. Control system 1 also features a high degree of automation and intelligence, automatically adjusting parameters according to different welding requirements, reducing manual intervention, and ensuring the stability and consistency of the welding process. Furthermore, by integrating multiple sensors and detection modules, the system achieves comprehensive monitoring of the welding process, further enhancing the system's reliability and safety.

[0039] The clamping system 2 consists of a base 21 and a clamping unit 22. The base 21 is used for modular positioning, and the clamping unit 22 is used for multi-station synchronous clamping of the longitudinal arm. Pressure closed-loop control is used to prevent workpiece deformation during clamping. With the cooperation of the base 21 and the clamping unit 22, high-precision modular positioning and multi-station synchronous stable clamping of the longitudinal arm workpiece can be achieved. The clamping force is dynamically adjusted in real time through pressure closed-loop control, which avoids plastic deformation of the workpiece caused by excessive clamping force and prevents workpiece displacement or vibration caused by insufficient clamping force. This provides accurate positioning guarantee for the subsequent laser composite welding process, ensuring that the robot body can accurately capture the welding position according to the preset trajectory. It effectively avoids defects such as weld seam offset and incomplete fusion caused by workpiece position deviation, further improving the repeatability of the welding process and the consistency of weld quality. At the same time, the multi-station synchronous clamping design also improves the workpiece clamping efficiency. Combined with the automated process of the control system, it shortens the production cycle.

[0040] Welding system 3 consists of a welding machine 31, a wire feeder 32, and a welding torch cleaning station 33. The welding machine 31 is used to achieve single-pass penetration of the longitudinal arm, the wire feeder 32 provides welding wire to the welding machine 31, and the welding torch cleaning station 33 automatically cleans the welding torch nozzle during welding intervals to remove slag, spatter, and oxide layers. Under the action of welding system 3, high-quality laser composite welding of the longitudinal arm of a new energy vehicle chassis can be achieved: the welding machine 31, with its precise laser energy output and arc-coordinated control, achieves single-pass penetration of the thick plate weld of the longitudinal arm, ensuring that the weld penetration depth meets design requirements and is free from burn-through, incomplete fusion, and other defects. The system ensures the structural strength of the longitudinal arm; the wire feeder 32 achieves stable and uniform feeding of the welding wire, and the welding wire melting speed is dynamically matched with the laser energy and welding speed to ensure consistent weld metal filling, resulting in smooth weld formation and uniform weld height, thus improving the appearance quality and consistency of the weld; the welding torch sandblasting cleaning station 33 automatically triggers the sandblasting cleaning program after each weld is completed, using high-speed jet sand particles to remove slag, spatter, and oxide layer from the inner wall and outlet of the welding torch nozzle, avoiding reduced gas shielding effect or arc instability due to nozzle blockage, reducing downtime caused by manual welding torch cleaning, and improving welding production efficiency. This not only ensures the welding quality of the longitudinal arm weld, such as uniform penetration, good formation, and absence of defects such as porosity or cracks, but also improves the stability and continuity of the welding process. Combined with the automated parameter adjustment function of the control system 1 and the precise positioning and clamping of the clamping system 2, it forms a complete solution from workpiece clamping and welding to quality assurance, effectively meeting the stringent requirements of new energy vehicle chassis longitudinal arms for welding precision, strength, and production efficiency.

[0041] The light source chamber 4 is used to provide stable laser energy for the welding machine 31, thereby ensuring that the synergistic effect of laser and electric arc is always kept at its best.

[0042] The auxiliary system 5 consists of a regulated power supply 51, a water cooling system 52, and a hydraulic station 53; wherein, the regulated power supply 51 is used to stabilize the output of three-phase voltage and suppress grid fluctuations, the water cooling system 52 is used to provide water cooling to the clamping unit 22, the welding machine 31, and the light source room 4, and the hydraulic station 53 is used to provide stable hydraulic power to the clamping unit 22.

[0043] With the combined action of the regulated power supply 51, water cooling system 52, and hydraulic station 53, the entire welding system can be provided with comprehensive basic operational support, ensuring that each core module performs optimally in a stable and reliable environment. The regulated power supply 51 has a three-phase input of 380V±15%, 50Hz; a three-phase output of 380V±1%, 50Hz; a rated power of 100kVA; overvoltage protection (420V±5V), overcurrent protection (150A±5A), and short-circuit protection (response time <0.1s). It is equipped with a voltage fluctuation compensation module (compensation range ±10%), effectively suppressing voltage spikes and harmonic interference in the power grid, providing a stable operating environment for the PLC control cabinet. 11. The robot control cabinet 12, welding machine 31, and high-precision electronic components in the light source room 4 are provided with a constant three-phase power supply to avoid control system command errors, robot trajectory deviations, or abnormal laser generator energy output caused by voltage fluctuations, thus ensuring the electrical stability of the entire system; the water cooling system 52 ensures that the temperature of each heat-generating component is always within the rated range, reducing component wear caused by overheating; the hydraulic station 53 provides continuous and uniform hydraulic power to the multi-station clamping mechanism of the clamping unit 22, and together with the pressure closed-loop control of the clamping system 2, ensures that the workpiece is always accurately positioned during the welding process, avoiding workpiece displacement or vibration caused by hydraulic power fluctuations.

[0044] Dust removal system 6 is used to capture fumes generated during welding. It purifies the fumes through high-efficiency filters and activated carbon adsorption, improving the welding working environment. Dust removal system 6 uses an air volume of 8000 m³ / h. 3 The mobile dust collector has a negative pressure of -12kPa, a length of 5m, a flexible suction arm that can rotate 360°, a filtration efficiency of 99.9% and a filtration accuracy of 0.3μm, and an activated carbon adsorption module with an adsorption capacity of 5kg. It is linked with the welding machine 31. When the welding machine 31 starts, the dust collection system 6 starts synchronously and shuts off after a 30-second delay after welding stops. It can efficiently capture the smoke and dust generated during the welding process (capture efficiency ≥98%) and achieve compliant emissions and environmental friendliness through a multi-stage purification process.

[0045] The welding station room 7 is used to provide a closed and safe welding environment, and the welding station room 7 is linked with the dust removal system 6 to achieve air circulation. Under the action of the welding station room 7, it can provide a closed, safe and environmentally controllable working space for the laser hybrid welding of the longitudinal arm of the new energy vehicle chassis, and achieve orderly air circulation through linkage with the dust removal system 6, forming a double guarantee of "isolation protection + environmental regulation".

[0046] In this embodiment, preferably, the PLC control cabinet 11 is connected to the robot control cabinet 12 through an interface for transmitting trajectory commands, connected to the hydraulic station 53 through an interface for controlling the clamping pressure, connected to the welding machine 31 through an interface for adjusting welding parameters, and connected to the dust removal system 6 through an interface for realizing linkage start and stop; the sensor data of the water cooling system 52 and the hydraulic clamping fixture are collected through the analog input module 4 - 20mA; the start and stop of the wire feeder 32, the gun cleaning station, and the voltage stabilizing power supply 51 are controlled through the digital output module; and the PLC control cabinet 11 is made of cold-rolled steel plate with an IP54 protection grade, and is equipped with a cooling fan with an air volume of 200m³ / h and a temperature and humidity sensor with a measurement range of 0 - 60°C / 20% - 90%RH. Furthermore, it can realize the intelligent management and precise control of the entire welding system.

[0047] In this embodiment, preferably, the robot control cabinet 12 is connected to the robot body through the EtherCAT bus, connected to the welding machine 31 through the IO interface for transmitting welding start / stop signals, and realizes data interaction with the PLC control cabinet through the Profinet interface; and the robot control cabinet 12 is adapted to a six-axis welding robot, and internally integrates a servo driver with six-axis independent drive, a motion control card supporting the EtherCAT bus, an emergency stop control circuit, and a robot motion database pre-storing 100 sets of longitudinal arm welding trajectory programs. Furthermore, it can realize the high-precision motion control of the six-axis welding robot, meet the precise following requirements of the complex curve welds of the longitudinal arm of the new energy vehicle chassis, and ensure that the welding torch always maintains the best angle with the weld; through the pre-stored 100 sets of longitudinal arm welding trajectory programs, the trajectory switching of different models can be completed within 30 seconds, adapting to the flexible production mode of multiple varieties and small batches, and reducing the changeover debugging time; with the high-speed data transmission of the EtherCAT bus (cycle ≤ 1ms), the real-time coordination of the robot body movement, the welding torch arc current (fluctuation ≤ 5A), and the laser energy output (error ≤ 2%) is realized, avoiding the defects of uneven weld penetration or lack of fusion caused by command delay; at the same time, through the Profinet data interaction with the PLC control cabinet 11, the workpiece positioning status of the clamping unit 22 is dynamically obtained. If the workpiece offset is detected, the trajectory correction command can be automatically triggered to ensure the consistency and reliability of the welding process.

[0048] In this embodiment, preferably, the clamping unit 22 includes eight sets of hydraulic clamping cylinders 221 and four sets of positioning pins 222. The hydraulic clamping cylinders 221 are used to fix the key force-bearing parts of the chassis longitudinal arm workpiece, and work with the four sets of positioning pins 222 to achieve accurate positioning and reliable clamping of the workpiece, preventing the workpiece from shifting due to thermal deformation or vibration during the welding process. The hydraulic clamping cylinders 221 have a cylinder diameter of 80mm, a stroke of 50mm, and a working pressure of 10-16MPa. The positioning pins 222 have a diameter of 20mm and a positioning accuracy of ±0.03mm. This provides uniform and stable clamping force to the key stress-bearing parts of the longitudinal arm workpiece (the working pressure of 10-16MPa can adapt to the clamping requirements of workpieces of different materials and thicknesses), and the 50mm stroke provides ample operating space for the insertion and removal of the workpiece; together with the 20mm diameter positioning pin with a positioning accuracy of ±0.03mm, high-precision modular positioning of the workpiece is achieved, ensuring that the longitudinal arm workpiece always maintains the preset position under multi-station synchronous clamping, effectively preventing workpiece displacement caused by thermal deformation, vibration or hydraulic power fluctuations during the welding process, providing a solid guarantee for the robot body to accurately capture the welding position according to the preset trajectory, and further improving the repeatability of the welding process and the consistency of weld quality.

[0049] In this embodiment, preferably, each hydraulic clamping cylinder 221 is equipped with a detection module 23. The detection module 23 integrates a pressure sensor 231 and a displacement sensor 232, which are used to monitor the clamping force of the hydraulic clamping cylinder 221 and the insertion depth of the positioning pin 222 in real time. This allows the monitoring data to be transmitted to the PLC control cabinet 11 in real time, forming a pressure closed-loop control circuit. When the clamping force exceeds the preset range or the insertion depth error of the positioning pin is large, the PLC control cabinet 11 immediately sends an adjustment command to the hydraulic station 53 to dynamically correct the hydraulic pressure or drive the positioning pin to fine-tune its position, ensuring that the clamping force of each hydraulic clamping cylinder remains stable. This not only avoids clamping force attenuation or clamping offset caused by hydraulic system fluctuations, component aging, or workpiece surface errors, but also promptly identifies abnormalities in the clamping process (such as positioning pin jamming or workpiece not fully fitting the base), preventing defects such as welding trajectory deviation, weld incomplete fusion, or workpiece thermal deformation caused by clamping problems. This further improves the reliability of the clamping system 2 and the consistency of welding quality, providing a solid clamping guarantee for high-precision laser composite welding of the longitudinal arm of the new energy vehicle chassis.

[0050] In this embodiment, preferably, the wire feeder 32 is connected to the welding machine 31 through a welding wire conduit, wherein the conduit has an inner diameter of 1.5 mm, a length of 5 m, and is made of nylon. This design provides a smooth and stable wire feeding channel: the 1.5mm inner diameter is compatible with commonly used 1.0-1.2mm diameter low-alloy welding wires, ensuring free movement of the wire within the guide tube while preventing wire wobbling due to excessive inner diameter, effectively reducing wire feeding resistance (≤5N); the 5m length matches the robot's range of motion, meeting the needs of the welding torch's complex trajectories during welding, and preventing limitations on robot movement due to insufficient guide tube length; the nylon material possesses excellent flexibility and wear resistance, withstanding fatigue stress from frequent bending of the welding torch (service life ≥12 months), and the smooth inner wall further reduces friction between the welding wire and the guide tube, preventing bending, jamming, or surface scratches during wire feeding. This ensures that the welding wire output from the wire feeder 32 can accurately and continuously enter the welding area of ​​the welding machine 31, forming a stable molten pool in conjunction with laser energy and arc, avoiding defects such as insufficient weld filling, uneven penetration, or unstable arc caused by poor wire feeding, ensuring the continuity of the welding process and the consistency of weld quality, while reducing guide tube maintenance and replacement costs.

[0051] In this embodiment, preferably, the output of the regulated power supply 51 is connected to the PLC control cabinet 11 and the robot control cabinet 12 via a three-phase five-wire cable to provide a stable power supply. The water cooling system 52 is connected to the light source room 4, the welding machine 31 and the clamping unit 22 via PU cooling water pipes. The hydraulic station 53 is connected to the clamping unit 22 via high-pressure oil pipes. This ensures the stability and reliability of power transmission, media flow, and signal interaction of each core module: the grounding protection design of the three-phase five-wire cable effectively avoids leakage hazards, providing a safe and constant power input for high-precision control units such as PLC control cabinet 11 and robot control cabinet 12, avoiding control command errors or electronic component damage caused by power transmission fluctuations; the PU cooling water pipe has excellent flexibility and chemical corrosion resistance, ensuring smooth circulation of the cooling medium between the light source room 4, welding machine 31, and clamping unit 22, removing excess heat from each heat-generating component in real time, keeping the component temperature within the rated operating range, and reducing equipment wear and lifespan reduction caused by overheating; the high-pressure oil pipe's high-pressure resistance and low leakage rate ensure that the hydraulic power output from the hydraulic station 53 is accurately transmitted to the eight sets of hydraulic clamping cylinders 221 of the clamping unit 22, and with the real-time monitoring of the detection module 23 and the closed-loop control of the PLC control cabinet 11, dynamic adjustment of clamping force and continuous stability of workpiece positioning are achieved, preventing workpiece displacement or welding trajectory deviation caused by hydraulic power transmission failure.

[0052] In this embodiment, preferably, the light source room 4 is equipped with an optical path monitoring sensor for real-time monitoring of laser energy. The light source room 4 is connected to the laser input interface of the welding machine 31 via an optical fiber with a core diameter of 50μm, a length of 10m, and a numerical aperture of 0.22. The outer layer of the optical fiber is armored for protection. This allows for real-time monitoring of laser energy attenuation and stability in the transmission path. When laser energy fluctuations exceed a preset threshold, feedback is quickly sent to the PLC control cabinet 11, triggering dynamic adjustment of the laser generator in the light source room 4 to ensure that the laser energy output to the welding machine 31 always maintains the design value. The small core diameter of the 50μm optical fiber, combined with the 0.22 numerical aperture, achieves high laser focusing (focused spot diameter ≤ 0.3mm) and high coupling efficiency (coupling efficiency ≥ 96%), allowing the laser energy to be precisely concentrated on the area to be melted in the longitudinal arm weld, improving the consistency of the weld depth (weld depth deviation ≤ 0.2mm). The 10m length matches the installation layout of the light source room 4 and the welding machine 31 in the welding station 7, avoiding problems caused by excessively short optical fibers. Limiting energy loss due to limited equipment adjustment space or excessive length (transmission loss ≤ 0.4dB / km); the armored protective outer layer has excellent resistance to mechanical shock (impact strength ≥ 15J) and bending resistance (bending radius ≥ 200mm), which can withstand the pulling of the robot body during movement and collisions in the workshop environment, preventing fiber breakage or signal interruption, ensuring the continuity of laser transmission (fault-free operation time ≥ 8000 hours), thus providing a stable and reliable laser energy input for the welding machine 31 to achieve coordinated control of laser and electric arc, avoiding defects such as incomplete fusion, burn-through or uneven penetration caused by laser energy fluctuations or transmission failures, and ensuring the welding quality and production efficiency of laser composite welding of the longitudinal arm of new energy vehicle chassis.

[0053] In this embodiment, preferably, the dust removal system 6 is connected to the dust collection control system inside the welding station 7 via a corrugated suction pipe. The corrugated suction pipe has an inner diameter of 150mm, a length of 6m, and its body is made of flame-retardant PVC material with an oxygen index ≥32. This ensures the dust removal system 6 can operate at 8000m... 3The high airflow rate ( / h) ensures smooth transmission, avoiding pressure loss due to insufficient pipe diameter (pressure loss ≤5%), and maintaining a stable negative pressure at the end of the flexible suction arm at -12kPa±1kPa. This allows for efficient capture of fumes generated at various workstations during longitudinal arm welding (such as the joint between the longitudinal arm and the reinforcing plate, and the arc weld section) (capture efficiency ≥98%). The 6m length matches the 360° rotation range of the suction arm within the welding station, ensuring that the coverage area is not limited by pipe length (coverage radius ≥3m), effectively covering all fume emission points of the complex curved weld seam of the longitudinal arm workpiece. The flame-retardant PVC material has an oxygen index ≥32, complying with GB standards. The fire protection requirements for welding workshops in the 50016-2014 "Code for Fire Protection Design of Buildings" are met. It can withstand welding sparks (temperature resistance ≥120℃), preventing pipe combustion caused by high temperatures and improving operational safety. The corrugated structure has good flexibility (bending radius ≥150mm), allowing it to follow the frequent rotation and swing of the dust collection arm, avoiding pipe breakage or airflow blockage due to bending (service life ≥18 months). Simultaneously, the 150mm inner diameter precisely matches the airflow output of the dust collector, ensuring the efficiency of the multi-stage purification process of the high-efficiency filter (99.9% filtration efficiency) and activated carbon adsorption module (5kg adsorption capacity). This ensures that the purified air meets emission standards (particulate matter concentration ≤10mg / m³, non-methane hydrocarbons ≤20mg / m³), achieving orderly air circulation and dual protection of "isolation and protection + environmental control" within the welding station, providing a safe and clean working environment for operators.

[0054] In this embodiment, preferably, the welding station 7 is made of all-aluminum alloy with an anodized surface treatment that eliminates light emission. The welding station 7 is equipped with an infrared grating 71 with a protection height of 2000mm and a response time of <0.01s, a smoke alarm 72 with a detection concentration of 0.1-10% LEL, emergency lighting 73 with a continuous power supply time of ≥90min, and a ventilation skylight 74 with an opening angle of 0-90° and electrically controlled. With the cooperation of the infrared grating 71, smoke alarm 72, emergency lighting 73, and ventilation skylight 74, the welding station 7 can achieve comprehensive safety protection and intelligent environmental control: the 2000mm infrared grating 71 covers key danger points such as the station entrance and the robot's movement area. When a person's limb or foreign object is detected entering, a high-speed triggering mechanism with a response time of <0.01s immediately sends an emergency stop command to the PLC control cabinet 11, simultaneously suspending the operation of the robot body, welding machine 31, and wire feeder 32 to prevent laser radiation and electrical hazards. In case of safety accidents such as arc burns or mechanical collisions; the smoke detector 72, with a detection concentration of 0.1-10% LEL, has a highly sensitive early fire warning function. It can identify smoke generated during welding due to abnormal situations such as oil burning on the workpiece surface or welding wire spatter igniting surrounding debris. When the smoke concentration reaches the threshold, on the one hand, it links the dust removal system 6 to increase the fan speed from 8000m³ / h to 10000m³ / h, enhancing the smoke and dust capture and discharge capabilities; on the other hand, it triggers the ventilation skylight 74 to open electrically to a maximum angle of 90°. The system ensures that smoke and harmful gases are expelled from the station building, preventing the fire from spreading or personnel from inhaling harmful gases. Emergency lighting 73, with a continuous power supply time of ≥90 minutes, automatically activates in the event of a sudden power outage, providing sufficient illumination for workers to safely shut down equipment, evacuate the site, or handle emergencies, meeting fire emergency regulations. The electrically operated ventilation skylight 74, with an opening angle of 0-90°, dynamically adjusts its opening angle based on real-time data from temperature and humidity sensors (integrated into the PLC control cabinet 11) during summer welding operations. For example, when the temperature inside the station exceeds 28°C, the skylight automatically opens to 60°, coordinating with the air circulation design of the dust removal system 6 to introduce fresh air into the station and lower the internal temperature. In winter, when temperatures are low, the skylight opens to 30°, maintaining air circulation while reducing heat loss, achieving precise control of temperature (18-28°C) and humidity (40%-60%RH) inside the station, providing stable environmental conditions for welding operations. Simultaneously, during non-welding periods, the skylight is opened for natural ventilation, reducing the energy consumption of the dust removal system. Furthermore, through the collaborative design of "active protection + intelligent early warning + environmental adaptation", a closed, safe and controllable station environment is provided for the laser composite welding operation of the longitudinal arm of the new energy vehicle chassis, ensuring the safety of the operators and the stability of the welding quality.

[0055] Working principle of the invention:

[0056] (I) Preliminary Preparations

[0057] Check the status of each component: confirm that the input voltage of the regulated power supply 51 is 380V±5%, the water level of the water cooling system 52 is ≥80%, the oil level of the hydraulic station 53 is ≥70%, and the filter element of the dust removal system 6 is not clogged (pressure difference ≤2kPa).

[0058] Start the system: Turn on the regulated power supply 54 in sequence → PLC control cabinet 11 → robot control cabinet 12 → water cooling system 52 → hydraulic station 53 → dust removal system 6. After each component completes its self-test (the indicator light is solid green), it will enter standby mode.

[0059] (ii) Clamping and positioning

[0060] According to the model of the longitudinal arm, the corresponding clamping program is called on the PLC touch screen, the positioning pin 222 extends (extends 20mm), and the hydraulic slide closes the mold to the preset position (error ±0.1mm).

[0061] Install the longitudinal arm into the fixture mold cavity, align the positioning hole with the positioning pin 222, start the clamping program, the hydraulic clamping cylinder 221 presses down (pressure 8-15MPa, depending on the material), after the pressure sensor 231 reports that the pressure has reached the standard (indicator light green), the clamping is complete.

[0062] (III) Welding Parameter Settings

[0063] Select the welding process on the PLC touch screen: laser power 0-6kW, MAG welding current 120-350A, welding speed 20-55mm / s, wire feed speed 6-15m / min;

[0064] Set auxiliary parameters: water cooling system 52 water temperature (the temperature connected to the light source room 4 is 20-22℃, and the temperature connected to the welding machine 31 is 23-25℃), dust removal system 6 air volume (8000m3 / h), and torch cleaning cycle (clean the torch once every 5 welds).

[0065] (iv) Welding process

[0066] Start the welding program: The PLC sends a command to the robot control cabinet 12, and the robot drives the welding machine 31 to move to the starting position of the weld. The vision inspection system (linked with the positioning inspection system) corrects the trajectory deviation (deviation ≤ 0.03mm).

[0067] Welding execution: Welding machine 31 outputs laser and electric arc, wire feeder 32 feeds wire synchronously, water cooling system 52 continuously cools, PLC monitors welding current (fluctuation ≤ ±5A), laser power (fluctuation ≤ ±2%), and molten pool temperature (1500-1800℃) in real time, and automatically adjusts parameters when abnormal (e.g., if the gap increases by 0.1mm, the laser power increases by 5%).

[0068] Interval cleaning: After every 5 weld seams are completed, the robot moves the welding torch to the welding torch sandblasting cleaning station 33 and performs the sandblasting → purging process (total time 10-18s). After cleaning, the robot returns to the welding position to continue the operation.

[0069] (v) Post-welding treatment

[0070] Welding stopped: After the weld is completed, the welding machine 31 stops outputting, the robot drives the welding gun back to the origin, the clamping unit 22 is released (the mold locking cylinder opens, the hydraulic mold closing opens, and the ejector pin automatically ejects the workpiece);

[0071] Workpiece removal: Remove the longitudinal arm to the inspection area, check the appearance of the weld (no porosity, slag inclusion), and the PLC automatically stores the welding data (parameters, time, monitoring results).

[0072] System maintenance: Shut down dust removal system 6 (delay 30s) → hydraulic station 53 → water cooling system 52 → robot control cabinet 12 → PLC control cabinet 11 → regulated power supply 51, clean the welding torch sandblasting station 33 to remove sandblasting residue, check the hydraulic oil and coolant levels, and replace the dust removal filter element (when the pressure difference is ≥5kPa).

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser composite welding system for the longitudinal arms of a new energy vehicle chassis, characterized in that, include: The control system (1) consists of a PLC control cabinet (11) and a robot control cabinet (12); wherein, the PLC control cabinet (11) is the core control unit of the system, which realizes parameter setting, real-time monitoring, fault alarm and data storage, and uploads data to the cloud platform through a 4G module; the robot control cabinet (12) is used to control the movement trajectory of the robot body. The clamping system (2) consists of a base (21) and a clamping unit (22); wherein the base (21) is used for modular positioning, and the clamping unit (22) is used for multi-station synchronous clamping of the longitudinal arm, and workpiece deformation is avoided by pressure closed-loop control; The welding system (3) consists of a welding machine (31), a wire feeder (32), and a welding torch sandblasting cleaning station (33); wherein, the welding machine (31) is used to achieve single-pass penetration of the longitudinal arm, the wire feeder (32) is used to provide welding wire to the welding machine (31), and the welding torch sandblasting cleaning station (33) is used to automatically clean the welding torch nozzle during the welding interval to remove welding slag, spatter and oxide layer; A light source room (4) is used to provide stable laser energy for the welding machine (31); The auxiliary system (5) consists of a regulated power supply (51), a water cooling system (52), and a hydraulic station (53); wherein, the regulated power supply (51) is used to stabilize the output of three-phase voltage and suppress grid fluctuations, the water cooling system (52) is used to provide water cooling to the clamping unit (22), the welding machine (31), and the light source room (4), and the hydraulic station (53) is used to provide stable hydraulic power to the clamping unit (22); The dust removal system (6) is used to capture the fumes generated during the welding process and purify them through high-efficiency filter and activated carbon adsorption to improve the welding working environment; The welding station (7) is used to provide a closed and safe welding environment, and the welding station (7) is linked with the dust removal system (6) to achieve air circulation.

2. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The PLC control cabinet (11) is connected to the robot control cabinet (12), hydraulic station (53), welding machine (31), and dust removal system (6) through an interface; it collects sensor data of water cooling system (52) and hydraulic mold clamping fixture through analog input module; it controls the start and stop of wire feeder (32), cleaning station and voltage regulator (51) through digital output module; and the PLC control cabinet (11) is made of cold-rolled steel plate with IP54 protection level, and has a built-in cooling fan with an air volume of 200m³ / h and a temperature and humidity sensor with a measurement range of 0-60℃ / 20%-90%RH.

3. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The robot control cabinet (12) is connected to the robot body via EtherCAT bus, connected to the welding machine (31) via IO interface, and interacts with the PLC control cabinet (11) via Profinet interface; the robot control cabinet (12) is adapted to a six-axis welding robot and integrates a six-axis independently driven servo driver, a motion control card supporting EtherCAT bus, an emergency stop control loop, and a robot motion database with 100 pre-stored longitudinal arm welding trajectory programs.

4. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The clamping unit (22) includes eight sets of hydraulic clamping cylinders (221) and four sets of positioning pins (222). The hydraulic clamping cylinders (221) are used to fix the key force-bearing parts of the chassis longitudinal arm workpiece. Together with the four sets of positioning pins (222), they achieve accurate positioning and reliable clamping of the workpiece, preventing the workpiece from shifting due to thermal deformation or vibration during the welding process. The hydraulic clamping cylinders (221) have a cylinder diameter of 80mm, a stroke of 50mm, and a working pressure of 10-16MPa. The positioning pins (222) have a diameter of 20mm and a positioning accuracy of ±0.03mm.

5. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 4, characterized in that, Each of the hydraulic clamping cylinders (221) is equipped with a detection module (23), which integrates a pressure sensor (231) and a displacement sensor (232) for real-time monitoring of the clamping force of the hydraulic clamping cylinder (221) and the insertion depth of the positioning pin (222).

6. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The wire feeder (32) is connected to the welding machine (31) through a welding wire conduit, wherein the conduit has an inner diameter of 1.5 mm, a length of 5 m, and is made of nylon.

7. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The output of the regulated power supply (51) is connected to the PLC control cabinet (11) and the robot control cabinet (12) via a three-phase five-wire cable to provide a stable power supply. The water cooling system (52) is connected to the light source room (4), the welding machine (31) and the clamping unit (22) via PU cooling water pipes. The hydraulic station (53) is connected to the clamping unit (22) via a high-pressure oil pipe.

8. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The light source room (4) is equipped with an optical path monitoring sensor for real-time monitoring of laser energy. The light source room (4) is connected to the laser input interface of the welding machine (31) via an optical fiber. The optical fiber has a core diameter of 50 μm, a length of 10 m, a numerical aperture of 0.22, and an outer layer of armor protection.

9. The laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The dust removal system (6) is connected to the dust control unit in the welding station (7) through a corrugated dust suction pipe. The inner diameter of the corrugated dust suction pipe is 150mm, the length is 6m, and the pipe body is made of flame-retardant PVC material with an oxygen index ≥32.

10. A laser composite welding system for the longitudinal arm of a new energy vehicle chassis according to claim 1, characterized in that, The welding station (7) is made of all aluminum alloy with an anodized surface and no light emission treatment. The welding station (7) is equipped with an infrared grating (71) with a protection height of 2000mm and a response time of <0.01s, a smoke alarm (72) with a detection concentration of 0.1-10%LEL, emergency lighting (73) with a continuous power supply time of ≥90min, and a ventilation skylight (74) with an opening angle of 0-90° and electrically controlled.

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